The Interpretation commentary series, published by Westminster John Knox Press, has been a popular academic resource for pastors and teachers for decades. 
The series, which covers Old and New Testament books, is complete.
The first volumes appeared in the early 1980’s and the final volumes appeared in the early 2000’s. There are 43 mid-size commentaries in the set.
Commentaries in the Interpretation series are known for their theological reflection and discussion of biblical themes.
Volumes are not technical in relation to the original languages of Scripture, so readers who have not been trained in Hebrews and Greek will not be hindered, and exegesis is not a central aim of the series.
Authors use the Revised Standard Version and the New Revised Standard Version as the basis for their comments.
The Interpretation series does not intend to meet every need of the reader, but focuses on Scripture, history, and theology.
“These volumes will not replace the historical critical commentary or homiletical aids to preaching,” writes the editors in the Series Preface.
“The purpose of this series is rather to provide a third kind of resources, a commentary which presents the integrated result of historical and theological work with the biblical text.” 
Generally, commentaries in the Interpretation series take a moderately-critical approach to Scripture.
Authors come from a variety of denominations, but share the goal of discussing the meaning of the text for the usefulness of the Church.
Note: See the Bible Commentaries Comparison Chart to see how the Interpretation series compares to dozens of other commentary series.
Interpretation Commentaries (INT): Reviews
Walter Brueggemann’s Genesis commentary is one of the most well-reviewed volumes in the series. From the review in Trinity Journal of Brueggemann’s Genesis commentary:
“The narratives in the book of Genesis are exciting stories from first to last, but we tend to lose some of that excitement either by reading too narrowly or by knowing the stories so well that the dramatic tension withers away.
One of the strong points of Brueggemann’s commentary is that he is able to make these stories come alive for the reader. Brueggemann is an able and insightful storyteller, often creating in the reader a new fascination for the text.” 
Another of the most highly-praised volumes is Richard B. Hays’ 1 Corinthians commentary. From the review in the Journal of the Evangelical Theological Society on Hays’ 1 Corinthians commentary:
“…for unpacking the meaning of the text, Hays’s contribution serves its purpose and readers well.
It achieves that difficult balance of addressing the essential issues and problems without bogging down those whose interests or expertise will not allow them to work through highly technical debates.
The book has no footnotes and only occasional references in the text to other resources, though Hays’s comments show his interaction with the research and literature — both ancient and modern — on the letter.” 
Commentaries in the Interpretation Series
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New Testament Volumes
Matthew – Douglas R. A. Hare | Published: 1993
Mark – Lamar Williamson, Jr. | Published: 1983
Luke – Fred B. Craddock | Published: 1990
John – Gerard Sloyan | Published: 1988
Acts – William H. Willimon | Published: 1988
Romans – Paul Achtemeier | Published: 1985
First Corinthians – Richard B. Hays | Published: 1997
Second Corinthians – Ernest Best | Published: 1987
Galatians – Charles B. Cousar | Published: 1982
Ephesians, Colossians and Philemon – Ralph P. Martin | Published: 1991
Philippians – Fred B. Craddock | Published: 1985
First and Second Thessalonians – Beverly Roberts Gaventa | Published: 1998
First & Second Timothy and Titus – Thomas C. Oden | Published: 1989
Hebrews – Thomas G. Long | Published: 1997
First & Second Peter, James and Jude – Pheme Perkins | Published: 1995
First, Second & Third John – D. Moody Smith | Published: 1991
Revelation – M. Eugene Boring | Published: 1989
Old Testament Volumes
Genesis – Walter Brueggemann | Published: 1982
Exodus – Terence E. Fretheim | Published: 1991
Leviticus – Samuel E. Balentine | Published: 2002
Numbers – Dennis T. Olson | Published: 1996
Deuteronomy – Patrick D. Miller | Published: 1990
Joshua – Jerome F.D. Creach | Published: 2002
Judges – J. Clinton McCann | Published: 2002
Ruth – Katharine Doob Sakenfeld | Published: 1999
First and Second Samuel – Walter Brueggemann | Published: 1990
First and Second Kings – Richard D. Nelson | Published: 1987
First and Second Chronicles – Steven S. Tuell | Published: 2001
Ezra & Nehemiah – Mark A. Throntveit | Published: 1992
Esther – Carol M. Bechtel | Published: 2002
Job – J. Gerald Janzen | Published: 19825
Psalms – James Luther Mays | Published: 1994
Proverbs – Leo G. Perdue | Published: 2000
Ecclesiastes – William P. Brown | Published: 2000
Song of Songs – Robert W. Jenson | Published: 2005
Isaiah: Chapters 1-39 – Christopher R. Seitz | Published: 1993
Isaiah: Chapters 40-66 – Paul D. Hanson | Published: 1995
Jeremiah – R. E. Clements | Published: 1988
Lamentations – F. W. Dobbs-Allsopp | Published: 2002
Ezekiel – Joseph Blenkinsopp | Published: 1990
Daniel – W. Sibley Towner | Published: 1984
Hosea to Micah – James Limburg | Published: 1988
Nahum to Malachi – Elizabeth Achtemeier | Published: 1986
The “Series Preface” can be found in any volume in the set.
Longman, T. Source: Trinity Journal, 4 no 1 Spr 1983, p 100-103. (subscription required)
Klein, William W. Source: Journal of the Evangelical Theological Society, 43 no 1 Mar 2000, p 149-152. (subscription required)